This invention relates in general to safety devices mounted within the interior of the vehicle for assisting in the protection of an occupant, such as during an impact situation.
In a vehicle impact condition, sudden large impact forces may be delivered to the occupant of the vehicle, such as in a rearward, frontal, or side impact. It is also common during large impact conditions for the head and limbs of the occupant to be forced against various panels and structures of the vehicle, thereby causing injury.
Various countermeasures have been taken to help reduce the degree of injury during the impact conditions. For example, passive restraint systems, such as air bags or air curtains have been implemented into vehicles. Generally, air bag systems are stored and packaged in deflated condition in storage areas within the passenger compartment of the motor vehicle. The air bag systems include sensors located at various points in the vehicle. Upon impact, the sensors are triggered thereby sending a signal to a gas generator or igniter. The gas generator operates to inflate the air bag when it receives a signal from the sensors. The air bags are located at various areas within the interior of the vehicle in which contact with the occupant is likely. For example, air bags are positioned in front of the driver and passenger locations, such as in the steering wheel and passenger side of the instrument panel. Air curtains are also positioned along the sides of the occupants, such as mounted at the edges of the headliner and propelled downwardly when inflated. Side air curtains have also been incorporated into the side portions of the seat backs.
It is also known to incorporate energy absorbing structures within the interior of the vehicle. These energy absorbing structures are located at areas of the vehicle which are likely to be contacted by the occupant, such as in knee bolster areas. Typically, the energy absorbing structures are made of materials, such as metal or plastic, which are designed to deform upon impact. The deformation of the material absorbs impact loads, thereby lessening injury to the occupant.
Although the air bags and energy absorbing structures assist in reducing injury to the vehicle occupants, they are not actively controllable depending on the severity of the impact situation.
This invention relates in general to safety devices mounted within the interior of the vehicle for assisting in the protection of an occupant, such as during an impact situation. In particular, a preferred embodiment of the present invention is an occupant protection apparatus including a housing and a bladder mounted relative to the housing. The bladder has at least one flexible wall and defines a chamber having an electrorheological or magnetorheological fluid disposed therein. The apparatus further includes a device for creating an electrical or magnetic field about a volume of the fluid to alter the effective viscosity of the fluid when the flexible wall is moved relative to the housing, thereby altering the acceleration rate of the flexible wall relative to the housing.
In another aspect of the invention, the apparatus may include a bladder defining a chamber having an electrorheological or magnetorheological fluid disposed therein. A wall is movably mounted relative to the housing such that movement of the wall alters the volume of the chamber. An open cell foam is disposed in the chamber such that the open cell foam contains gas within a portion of the cells and contains the fluid within another portion of the cells, such that the gas is generally interspersed within the fluid. The apparatus further includes a device for creating an electrical or magnetic field about a volume of the fluid to alter the effective viscosity of the fluid when the wall is moved to decrease the volume of the chamber by the compression of the gas, thereby altering the acceleration rate of the wall relative to the housing.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.